Dry washing biodiesel purification using fumed silica sorbent

• Autor(a) principal: Catarino, Mónica
• Data de Publicação: 2020
• Outros Autores: Ferreira, Eduardo, Soares Dias, A. P., Gomes, João
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.21/12718
• topic: Biodiesel purification; Low-grade fat; Ca-based catalyst; Dry wash; Silica; Sorbent regeneration

Aiming the decarbonization of the transport sector, biodiesel, obtained by alcoholysis of oils or animal fats, is currently mixed with conventional fossil diesel. For this purpose, biodiesel has to comply with the established quality standards and, therefore, the production process comprises purification steps, which need huge volumes of water. Thus, the biodiesel purification procedure must be improved in order to provide a greener and low-cost renewable fuel. Biodiesel (FAME) produced by methanolysis of soybean and waste frying oils over a heterogeneous calcium - based catalyst was purified by dry washing, using commercial silica sorbent (Sipernat 22 from Evonik). ATR-FTIR spectra of post-purification sorbents showed that silica was effective to remove unreacted oil species, glycerin and Ca soap from biodiesel and, contrary to the previously reported in the literature, it was also able to remove leached calcium from the biodiesel. For both feedsotcks, the highest purity was reached for the sorption test carried out at 45 degrees C during 60 min. Sorbent regeneration was evaluated using acetone, methanol, and isopropanol alcohols at room temperature during short contact time (5 min for 1 g of sorbent and 20 mL of solvent). All the tested solvents were effective to remove the adsorbed species from silica surface.